Early pituitary-adrenal responses and retinopathy of prematurity in very low birth weight infants.

This longitudinal prospective study aimed to investigate the relationship between pituitary-adrenal responses and severity of retinopathy of prematurity (ROP) in 92 preterm, very low birth weight infants < or = 30 wk gestation. The human corticotropin releasing hormone stimulation test was performed on these infants at D 7 and 14 of postnatal life. Univariate analysis revealed significant associations between severity of ROP and gestational age (r = -0.53, p < 0.0001), birth weight (r = -0.56, p < 0.0001), Apgar score at 1 min (r = -0.27, p < 0.05), Clinical Risk Index for Babies score (r = 0.48, p < 0.0001), duration of mechanical ventilation (r = 0.48, p < 0.0001), oxygen dependency (r = 0.48, p < 0.0001), and length of hospitalization (r = 0.49, p < 0.0001). The stage of ROP was also significantly associated with the basal and peak plasma ACTH (r > -0.22, p < 0.05) and peak serum cortisol (r = -0.21, p = 0.05) at d 7. Multivariate analysis using the classification and regression trees indicated that the two most influential risk factors affecting the development of advanced stages of ROP (> or = stage 3) were i) birth weight and ii) oxygen dependency at 28 d of life or at 36 wk postconceptional age. Our findings suggest that early endogenous or stimulated pituitary-adrenal responses are not independent risk factors associated with the development of severe ROP. Low birth weight and prolonged oxygen exposure are likely to be important factors that influence the degree of damage inflicted on the retina.